That is a tough one. I've done this sort of thing before, but in 3D software, and I already had a displacement (black to white) map to use for extruding the 3D surface. I then used a procedural texture color gradient on the Y axis of the model to apply my chosen colors to the model's contours, which could be controlled by editing the spacing of colors within the gradient texture itself. The final step was to render the image from the top view in a parallel camera mode, producing a flat 2D image with no perspective distortion. This could then be composited with the original topo map.
I don't see any easy way to automate part of this in GIMP, other than perhaps using a blur filter to help with the blending between contours (doubtful if that will even give great results). It's also hard to try without seeing an example map, because some topo maps are a pain this way - they often have things like numbers overlaid on the lines, which creates many little gaps that must be compensated for when selecting a specific area. Hope you find a way. Marc _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
